High Density Groundwater Flow, Major-ion Chemistry and Field Experiments in a Closed Basin: Fuente de Piedra Playa Lake (Spain)

Abstract

This study presents the results of 10 years of field investigation in Fuente de Piedra Playa Lake located in southern Spain. These field observations along the playa's shore revealed evidence of a forced convective flow and the existence of density interface below the playa basin. An upward flux of groundwater from underlying formations could be a considerable part of its recharge. These groundwater fluxes mostly occur during the summer when the playa is a salt-flat. On this basis, a numerical model was applied in order to examine the effects of upward fluxes on the geometry of the salinity interface. On the other hand, hydrochemical classification and stable isotope analyses were employed to determine the processes that control surface water and groundwater chemistry. Water budget results also confirm the conceptual model developed of the system.